Long-Term Outcomes of Anatomical and Extra-Anatomical Bypass for the Treatment of Unilateral Iliac Artery Lesions a Systematic Review Aggregated Data and Individual Participant Data Meta-Analysis.

Background: We investigated the long-term safety and efficacy of anatomical and extra-anatomical bypass for the treatment of unilateral iliac artery disease.

Methods: A systematic search on PubMed, Scopus and Web of science for articles published by June 2023 was performed. We implemented a 2-stage individual participant data meta-analysis and pooled survival probabilities using the multivariate methodology of DerSimonian and Laird. The primary endpoint was primary patency at 5 and 10 years of follow-up.

Results: Ten studies encompassing 1,907 patients were included. The 5- and 10-year pooled patency rates for anatomical bypass were 83.27% (95% confidence interval (CI): 69.99-99.07) and 77.30% (95% CI: 60.32-99.04), respectively, with a mean primary patency time representing the duration individuals remained event-free for 10.08 years (95% CI: 8.05-10.97). The 5- and 10-year pooled primary patency estimates for extra-anatomical bypass were 77.02% (95% CI: 66.79-88.80) and 68.54% (95% CI: 53.32-88.09), respectively, with a mean primary patency time of 9.25 years, (95% CI: 7.21-9.68). Upon 2-stage individual participant data meta-analysis, anatomical bypass displayed a decreased risk for loss of primary patency compared to extra-anatomical bypass, hazard ratio 0.51 (95% CI: 0.30-0.85). The 5- and 10-year secondary patency estimates for anatomical bypass were 96.83% (95% CI: 90.28-100) and 96.13% (95% CI: 88.72-100), respectively. The 5- and 10-year secondary patency estimates for extra-anatomical bypass were 91.39% (95% CI: 84.32-99.04) and 85.05% (95% CI: 74.43-97.18), respectively, with non-statistically significant difference between the 2 groups. The 5- and 10-year survival for patients undergoing anatomical bypass were 67.99% (95% CI: 53.84-85.85) and 41.09% (95% CI: 25.36-66.57), respectively. The 5- and 10-year survival for extra-anatomical bypass were 70.67% (95% CI: 56.76-87.98) and 34.85% (95% CI: 19.76-61.44), respectively. The mean survival time was 6.92 years (95% CI: 5.56-7.89) for the anatomical and 6.78 years (95% CI: 5.31-7.63) for the extra-anatomical groups. The pooled overall 30-day mortality was 2.32% (95% CI: 1.12-3.87) with metaregression analysis displaying a negative association between the year of publication and mortality (β =-0.0065, P < 0.01). Further analysis displayed a 30-day mortality of 1.29% (95% CI: 0.56-2.26) versus 4.02% (95% CI: 1.78-7.03), (P = 0.02) for studies published after and before the year 2000. Non-statistically significant differences were identified between the 2 groups concerning long-term and 30-day mortality outcomes.

Conclusions: While we have demonstrated favorable long-term primary and secondary patency outcomes for both surgical techniques, anatomical bypass exhibited a reduced risk of primary patency loss potentially reflecting its inherent capacity to circumvent the anticipated disease progression in the distal aorta and the contralateral donor artery. The reduction in perioperative mortality observed in our review, coupled with the anachronistic demographic characteristics and inclusion criteria presented in the existing literature, underscores the imperative necessity for contemporary research.